CN106891321B

CN106891321B - Working device

Info

Publication number: CN106891321B
Application number: CN201611048817.1A
Authority: CN
Inventors: 高野健; 木村悟
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2015-12-17
Filing date: 2016-11-23
Publication date: 2021-06-11
Anticipated expiration: 2036-11-23
Also published as: JP2017109270A; CN106891321A; JP6572439B2; US10259115B2; US20170173792A1

Abstract

The invention provides a working device. The working device is provided with: a base part; a movable portion to which the end effector is attached; a plurality of link mechanisms connecting the base portion and the movable portion; a plurality of actuators fixed to the base portion and respectively driving the plurality of link mechanisms; and a control unit that moves the end effector by operating the plurality of actuators. Some of the plurality of linkages have joint portions. The control section has a joint angle determination section that determines whether or not the bending angle of the certain link mechanism at the joint section is within a movable range.

Description

Working device

Technical Field

The present invention relates to a working device that performs work by an end effector attached to a movable portion that moves via a plurality of link mechanisms.

Background

As a working apparatus used in industrial applications, a parallel link robot (parallel link robot) having a structure in which a movable portion to which an end effector such as a component holding tool is attached is driven by a plurality of link mechanisms is known. In this parallel link robot, it is difficult to intuitively grasp the correspondence between the axial coordinates indicating the rotational position of the motor that drives the link mechanism and the spatial position of the movable portion, due to the characteristics of the mechanism structure. Therefore, a movable range in which the movable portion can safely move without mechanical interference during operation of the parallel link robot is divided in association with an axis coordinate indicating a rotational position of the motor, and stored in advance as movable region data (see, for example, japanese patent laid-open nos. 2003-25263 and 2014-217913).

In the prior art disclosed in japanese patent application laid-open No. 2003-25263, a movable region in which the movement of a movable portion is permitted is stored while being divided into a cylindrical shape in advance, the current position and posture are calculated based on a detection signal of a position detection portion during the movement, and the calculated position and posture are compared with the stored movable region, thereby coping with the case where the movable region interferes or cannot be controlled. In addition, the prior art disclosed in japanese patent application laid-open No. 2014-217913 describes the following examples: in addition to a first movable range indicating a movable range of a structure divided based on a structure of the robot, a second movable range smaller than the first movable range is preset on a safety side, and a warning is given when the current position deviates from the second movable range.

Disclosure of Invention

The working device is provided with: a base part; a movable portion for fitting an end effector; a plurality of link mechanisms that connect the base portion and the movable portion; a plurality of actuators fixed to the base portion and respectively driving the plurality of link mechanisms; and a control section that moves the end effector by operating the plurality of actuators, some of the plurality of link mechanisms having joint portions, the control section having a joint angle determination section that determines whether or not a bending angle of the some of the link mechanisms at the joint portions is within an operable range.

The working device can prevent interference caused by bending action beyond the movable action range at the joint part.

Drawings

Fig. 1 is a perspective view showing the overall configuration of a working device according to an embodiment.

Fig. 2 is a perspective view showing a structure of a working robot incorporated in the working device according to the embodiment.

Fig. 3A to 3C are explanatory views of the bending angle of the first joint portion used in the working robot incorporated in the working device according to the embodiment.

Fig. 4A to 4C are explanatory views of the bending angle of the first joint portion used in the working robot incorporated in the working device according to the embodiment.

Fig. 5 is a block diagram showing a configuration of a control system of a working device according to an embodiment.

Fig. 6A and 6B are graphs showing operable ranges in combinations of 2-directional bending angles of the first joint portion and the second joint portion used in the working robot incorporated in the working device according to the embodiment.

Fig. 7 is a graph showing an example of a display of a non-operable position in the operation mode of the working robot incorporated in the working device according to the embodiment.

Detailed Description

The overall configuration of the working device 1 according to the embodiment will be described with reference to fig. 1. In fig. 1, a mounting table 3 is provided on a work base 2a on the upper surface of a base 2, and a work 4 to be worked is placed on the mounting table 3. The component 5 is assembled to the workpiece 4 by a working robot 7 described below.

A corner post 2b is erected at a corner portion of the work base 2a, and a horizontal stand 6 is erected at an upper end portion of the corner post 2 b. A working robot 7 having a parallel link mechanism is disposed on the lower surface of the stand 6. The work robot 7 performs an operation of holding the component 5 by the end effector 8 and assembling the component 5 to the workpiece 4.

An operation panel 9 having a touch panel is disposed on a side surface of the stand 6. The operation and instruction input for operation instruction are performed by touch operation input through the operation panel 9 with respect to the work robot 7. In the coordinate system of the working device 1, a horizontal direction in the right-left direction when viewed from the front of the working device is defined as an X-axis, an axis orthogonal to the X-axis in the front-rear direction is defined as a Y-axis, and axes orthogonal to the X-axis and the Y-axis in the up-down direction are defined as a Z-axis.

Next, the structure and function of the working robot 7 will be described with reference to fig. 2. The working robot 7 is a parallel link robot having 6 degrees of freedom. The base portion 7a shown in fig. 2 is a mechanism portion for operating each portion described below by incorporating a drive source in the working robot 7, and is attached to the lower surface of the mount 6. That is, the base portion 7a is fixed and fastened to the lower surface of the mount 6 via an annular fitting portion 12 disposed at the center portion. At the trisected arrangement positions in the circumferential direction, 3 motor brackets 11 (

brackets

11a, 11b, 11c) are provided extending in the radial direction from the fitting portion 12. The motor bracket 11 and the mounting portion 12 constitute a work robot main body portion 13 in the work robot 7.

In each

motor bracket

11, 2 motors M of a servo control system are arranged in series in a posture in which drive shafts face each other. That is, the carriage 11a is fixed in a posture in which the drive shafts face each other, by a motor M1 including the encoder E1 and the brake B1 coaxially arranged, and a motor M2 including the encoder E2 and the brake B2 coaxially arranged.

Further, the carriage 11B is fixed in a posture in which the drive shafts face each other, by a motor M3 including an encoder E3 and a brake B3 coaxially arranged, and a motor M4 including an encoder E4 and a brake B4 coaxially arranged. Further, the carriage 11c is fixed in a posture in which the drive shafts face each other, by a motor M5 including an encoder E5 and a brake B5 coaxially arranged, and a motor M6 including an encoder E6 and a brake B6 coaxially arranged.

In the following description, the 6 elements of the motors M1 to M6, the brake units B1 to B6, and the encoders E1 to E6 included in the working robot 7 are collectively referred to simply as the motor M, the brake unit B, and the encoder E, except for the case where the elements need to be individually identified and distinguished.

Here, the function of the motor M disposed and fixed to the base portion 7a of the working robot 7 as described above will be described by taking as a representative example the motor M5 in which the drive shaft 14 is clearly shown in fig. 2. An arm member 15 extending radially outward from the center of the base portion 7a is coupled to the drive shaft 14 of the motor M5. The drive shaft 14 is rotated in the forward and reverse directions by driving the motor M5, and the arm member 15 swings about the drive shaft 14 in the vertical plane.

A link member 17 extending downward is coupled to a distal end portion of the arm member 15 via a first joint portion 16 as a universal joint. Further, the lower end portion of the link member 17 is coupled to the movable portion 20 via a second joint portion 18 as a universal joint. An end effector 8 is attached to the lower surface of the movable portion 20, and in the example shown here, an example of a component gripping tool having 2 gripping claws 8a is shown as the end effector 8.

In the above configuration, the arm member 15, the first joint portion 16, the link member 17, and the second joint portion 18 constitute a link mechanism 19 that moves the movable portion 20. The link mechanism 19 is provided for all of the 6 motors M (motor M1 to motor M6) fixed to the base portion 7a, and each motor M operates as a power source of the corresponding link mechanism 19.

That is, the working robot 7 according to the present embodiment includes: a movable portion 20 to which the end effector 8 is attached; a plurality of link mechanisms 19 for connecting the base portion 7a and the movable portion 20; and a plurality of (6 in this case) motors M (motors M1 to M6) which are actuators provided independently for each link mechanism 19, operate as power sources of the link mechanisms 19, and are fixed to the base portion 7 a.

During the operation of the link mechanism 19 by the motor M, the encoder E outputs pulse data indicating the rotation amount of the motor M. In other words, the encoder E functions as a position detecting unit that outputs coordinate data indicating the operation amount of the link mechanism 19. In addition, during the operation of the link mechanism 19 by the motor M, the motor M is braked by operating the brake portion B to restrict the operation of the link mechanism 19.

In order to freely define the position and posture of the movable portion 20 provided in the working robot 7 in the fixed coordinate system set in the space on the working base 2a of the working device 1, the movable portion 20 needs to have 6 degrees of freedom. In the working robot 7 of the present embodiment, the position and posture of the movable portion 20 can be freely set by providing 6 sets of the link mechanism 19 and the motor M having the above-described configuration and controlling each set of the motor M independently.

Here, the position and the posture of the movable portion 20 are changed in accordance with the rotation angle of the 6 arm members 15, and the position and the posture of the movable portion 20 can be obtained from the coordinate data output from the encoder E provided in each motor M as the position detection portion described above. In addition, in a case where the position and the posture of the movable portion 20 need to be held in a teaching task or the like for teaching a task operation to the working robot 7 with assistance, the brake portion B is operated at a desired timing to brake the motor M, and the movable portion 20 stops operating to hold the position.

Next, the detailed structure of the first joint portion 16 and the second joint portion 18 constituting the link mechanism 19 and the bending angle at these joint portions will be described with reference to fig. 3A to 3C and fig. 4A to 4C. Fig. 3A shows a detailed configuration of the first joint portion 16 joined to the front end portion of the arm member 15. At the distal end portion of the arm member 15, the first rotation shaft 21a is pivotally supported by a bearing portion 22 in a cantilever support manner. The first rotation shaft 21a is supported so as to be rotatable about a rotation center line a1 in the horizontal direction, and is supported so as to be rotatable in the horizontal direction perpendicular to the extending direction of the arm member 15.

The first rotary shaft 21a is coupled to a second rotary shaft 21b which has a rotation center line C1 perpendicular to the rotation center line a1 and intersects with each other. The second rotation shaft 21b is pivotally supported by a bearing portion 23 of approximately コ shape coupled to the upper end portion of the link member 17 in a double-arm support manner. With this configuration, the link member 17 is rotatable about the rotation center line C1. In the above configuration, the first rotation shaft 21a and the second rotation shaft 21b constitute the cross joint portion 21. The cross joint portion 21 constitutes the first joint portion 16 as a universal joint together with the bearing portion 22 and the bearing portion 23. That is, the first joint portion 16 is a universal joint having a first rotation shaft 21a and a second rotation shaft 21b intersecting each other.

In the operation of the link mechanism 19 in the working robot 7, the first joint portion 16 transmits the operation of the arm member 15 to the link member 17 while bending. Fig. 3B and 3C show the bending angle of the first joint portion 16 when the link mechanism 19 operates. That is, as shown in fig. 3B, the first bending angle α 1 is an angle centered on the rotation center line a1 formed by the extension line of the arm member 15 and the axis of the link member 17. The second bending angle β 1 shown in fig. 3C is an angle around the rotation center line C1 formed by the Z-axis (see fig. 1 and 2) and the axis of the link member 17.

Fig. 4A shows a detailed configuration of the second joint portion 18 coupled to the lower end portion of the link member 17. At the lower end of the link member 17, the first rotation shaft 25a is supported by a double-arm support via a bearing portion 26 having a substantially コ shape. The first rotation shaft 25a is pivotally supported in a direction orthogonal to the axial direction of the link member 17, and the link member 17 is rotatable about a rotation center line a 2.

The first rotation shaft 25a is coupled to a second rotation shaft 25b that has a rotation center line C2 perpendicular to the rotation center line a2 and intersects with each other. Second rotation shaft 25b is pivotally supported by bearing portion 27 having a substantially コ -shaped double-arm support system, and bearing portion 27 is coupled to the upper surface of movable portion 20 in a state where rotation about an axis perpendicular to the upper surface of movable portion 20 is permitted. The second rotation shaft 25b is rotatable about the rotation center line C2. In the above configuration, the first rotation shaft 25a and the second rotation shaft 25b constitute the cross joint portion 25. The cross joint portion 25 constitutes the second joint portion 18 as a universal joint together with the bearing portion 26 and the bearing portion 27. That is, the second joint portion 18 is a universal joint having a first rotation shaft 25a and a second rotation shaft 25b intersecting each other.

In the operation of the link mechanism 19 in the working robot 7, the second joint portion 18 is bent while transmitting the operation from the link member 17 to the movable portion 20. Fig. 4B and 4C show the bending angle of the second joint part 18 when the link mechanism 19 operates. That is, as shown in fig. 4B, the first bending angle α 2 is an angle centered on the rotation center line a2 formed by the Z-axis and the axis of the link member 17. The second bending angle β 2 shown in fig. 3C is an angle centered on the rotation center line C2 formed by the imaginary line 20a perpendicularly intersecting the movable portion 20 and the axis of the link member 17.

When the movable portion 20 is driven via the link mechanism 19, the first joint portion 16 and the second joint portion 18 are bent in each link member 17, and drive is transmitted to the movable portion 20. At this time, the first joint part 16 and the second joint part 18 are not allowed to be bent without limitation, and are allowed to be bent only within a movable range limited by the shape of the mechanism part constituting the first joint part 16 and the second joint part 18. For example, in the first joint portion 16, a bending operation in which the bearing portion 23 interferes with the arm member 15 is not allowed. Similarly, the second joint part 18 does not allow a bending operation in which the bearing part 26 and the bearing part 27 interfere with each other.

When the motor M is driven by an operation command exceeding the operable range, the motor M is driven in a state where mechanical interference occurs between the first joint 16 and the second joint 18, and as a result, there is a possibility that a trouble such as damage or breakage of a mechanism portion may occur due to overload of the motor M. In the working device 1 shown in the present embodiment, the condition of the bending angle corresponding to the normal bending state in the first joint part 16 and the second joint part 18 is previously defined as the operable range data so as to avoid outputting an operation command to the motor M such that the first joint part 16 and the second joint part 18 perform the bending operation beyond the operable range.

That is, operable range data indicating a combination of the first bending angle α 1 and the second bending angle β 1 corresponding to the normal bending state in the first joint portion 16 and a combination of the first bending angle α 2 and the second bending angle β 2 corresponding to the normal bending state in the second joint portion 18 are created and stored in advance. Then, when controlling the motor M to move the movable portion 20 based on the operation pattern stored in advance, the presence or absence of a failure is determined with reference to the operable range data.

Next, the configuration of the control system of the working device 1 will be described with reference to fig. 5. In fig. 5, the control unit 30 has a function of moving the end effector 8 by operating the motors M as a plurality of actuators, and includes an interface unit 31, a storage unit 32, an operation unit 33, a teaching unit 34, an editing unit 35, and a determination unit 36.

Further, the control unit 30 is connected with a display unit 37, an operation/input unit 38, and a computer 39. The display unit 37 and the operation/input unit 38 have a display function and an operation input function incorporated in the operation panel 9. The display unit 37 displays various screens on a display screen such as a liquid crystal panel of the operation panel 9. The operation/input unit 38 performs various operation inputs by performing a touch operation by an operator operating the operation panel 9.

The computer 39 is an external computer connected to the work apparatus 1 via a LAN system or the like. As the processing functions of the computer 39, there are included: storing, creating, editing and the like of the action mode; data management such as uploading and downloading of various data including an operation mode; output of operation instruction data necessary for the operation of the work apparatus 1, and the like. That is, the computer 39 has a function capable of executing a part or all of the functions of the control unit 30 instead of the control unit 30 as necessary.

The interface unit 31 is connected to a motor M (motor M1 to motor M6) and an encoder E (encoder E1 to encoder E6) attached thereto. The end effector 8 can be moved by transmitting a control command from the controller 30 to the motors M1 to M6, which are a plurality of actuators, via the interface unit 31 to operate the motors M1 to M6. Thereby, a predetermined job operation is executed. The functions of operating the motors M1 to M6 are executed by the processing functions provided in the operating unit 33. The axis coordinate data output from the encoder E (the encoder E1 to the encoder E6) is acquired via the interface unit 31, and is transferred to the storage unit 32 and the teaching unit 34, which will be described below.

The storage unit 32 includes an axis coordinate storage unit 32a, an end effector coordinate storage unit 32b, a device data storage unit 32c, and a determination information storage unit 32 d. Both the axis coordinate storage unit 32a and the end effector coordinate storage unit 32b are operation pattern storage units that store operation patterns of the work operation performed by the end effector 8. The axis coordinate storage unit 32a stores operation patterns described by axis coordinate data (θ 1 to θ 6) indicating the respective axis rotation positions of the plurality of motors M (motor M1 to motor M6). The end effector coordinate storage unit 32b stores an operation pattern described by the geometric three-dimensional coordinate data (X, Y, Z, θ x, θ y, and θ z) of the end effector 8. The three-dimensional coordinate data (X, Y, Z, θ x, θ y, θ z) of the end effector 8 and the axis coordinate data (θ 1, θ 2, θ 3, θ 4, θ 5, θ 6) are in one-to-one correspondence, and can be converted into data by computation.

The device data storage unit 32c stores various data for specifying device data such as dimensions of the mechanism portion constituting the working robot 7, and the determination unit 36 refers to these data for various determinations. For example, in the judgment of the joint angle judging section 36d as to whether or not the bending operation is possible, the presence or absence of mechanical interference in the bending operation of the first joint section 16 and the second joint section 18 is judged based on the data contained in the device data storage section 32 c. The judgment information storage unit 32d stores judgment information such as a judgment threshold used for various judgments by the judgment unit 36 described below. These pieces of judgment information include: the operable range data of the conditions of the bending angles corresponding to the normal bending state in the first joint part 16 and the second joint part 18 are predetermined.

Fig. 6A and 6B show examples of the operable range data included in the determination information storage unit 32 d. The operable range diagram 40A shown in fig. 6A specifies conditions of the bending angle corresponding to the normal bending state in the first joint portion 16. That is, in the operational range diagram 40A, in the combination of the first bending angle α 1 and the second bending angle β 1 defined by the orthogonal coordinate in which the abscissa axis is constituted by the first bending angle α 1 and the ordinate axis is constituted by the second bending angle β 1, the upper limit line L1 is defined, and the upper limit line L1 indicates the limit of the region in which the bending operation can be normally performed without causing mechanical interference with the mechanism portion of the first joint part 16. The upper limit line L1 indicates the upper limit value of the second bending angle β 1 allowed in accordance with the first bending angle α 1 shown on the horizontal axis, and indicates that a normal bending operation can be realized by a combination of the first bending angle α 1 and the second bending angle β 1 belonging to a region lower than the upper limit line L1.

Fig. 6B specifies the conditions of the bending angle corresponding to the normal bending state in the second joint portion 18. That is, in the operational range diagram 40B, an upper limit line L2 is defined in a combination of the first bending angle α 2 and the second bending angle β 2 defined by an orthogonal coordinate in which the horizontal axis is defined by the first bending angle α 2 and the vertical axis is defined by the second bending angle β 2, and the upper limit line L2 indicates a limit of a region in which the bending operation can be normally performed without causing mechanical interference with the mechanism portion of the second joint part 18. Similarly, the upper limit line L2 represents the upper limit value of the second bending angle β 2 allowed in accordance with the first bending angle α 2 shown on the horizontal axis, and represents that a normal bending operation can be realized by a combination of the first bending angle α 2 and the second bending angle β 2 belonging to a region lower than the upper limit line L2.

The operation unit 33 has a function of driving the motors M (M1 to M6) in accordance with the operation mode stored in the axis coordinate storage unit 32a or the end effector coordinate storage unit 32b as the operation mode storage unit. That is, the operation unit 33 of the controller 30 transmits a control command to the motors M1 to M6 via the interface unit 31 according to the operation mode, and operates the motors M1 to M6. The teaching section 34 executes teaching processing for teaching the operation of the task executed by the end effector 8.

The teaching process is performed as follows: the operator performs an operation of making the teaching function effective to the control section 30 via the operation/input section 38, for example, an operation of starting a teaching program stored in advance. In the teaching process, information output from the encoder E of each motor M is read at a constant cycle via the interface unit 31 and written into the axis coordinate storage unit 32a as axis coordinate data (θ 1, θ 2, θ 3, θ 4, θ 5, and θ 6) for each motor M. The editing unit 35 performs data editing processing for creating an operation pattern based on the axis coordinate data written in the axis coordinate storage unit 32 a.

The determination unit 36 includes a motor speed determination unit 36a, a motor torque determination unit 36b, a movable range determination unit 36c, and a joint angle determination unit 36 d. The motor speed determination unit 36a determines whether or not the rotation speed obtained by the motor M is within the range of the allowable rotation number allowed for the motor M based on the determination information stored in the determination information storage unit 32d in the working operation for operating the motor M according to the operation mode stored in the axis coordinate storage unit 32a or the end effector coordinate storage unit 32 b.

Similarly, the motor torque determination unit 36b determines whether or not the torque obtained by the motor M is within the allowable torque range allowed for the motor M based on the determination information stored in the determination information storage unit 32d during the working operation for operating the motor M according to the stored operation mode. The movable range determining unit 36c determines whether or not the movement range obtained in the movable unit 20 is within the movable range previously stored in the determination information storage unit 32d during the working operation for operating the motor M according to the stored operation pattern.

The joint angle determination unit 36d determines whether or not the bending angle of the link mechanism 19 in the first joint portion 16 and the second joint portion 18 is within the movable range in the working operation in which the motor M is operated using the operation mode stored in the shaft coordinate storage unit 32a or the end effector coordinate storage unit 32 b. That is, with respect to the first joint portion 16, which is a universal joint having the first rotation shaft 21a and the second rotation shaft 21b intersecting each other, it is determined whether or not a combination of the first bending angle α 1 centered on the first rotation shaft 21a and the second bending angle β 1 centered on the second rotation shaft 21b is within the operable range (the region below the upper limit line L1) defined by the operable range diagram 40A shown in fig. 6A.

Similarly, it is determined whether or not a combination of a first bending angle α 2 around the first rotation shaft 25a and a second bending angle β 2 around the second rotation shaft 25B is within the operable range (the region below the upper limit line L2) defined by the operable range diagram 40B shown in fig. 6B, with respect to the second joint portion 18, which is a universal joint having the first rotation shaft 25a and the second rotation shaft 25B intersecting each other.

In the determination process by the joint angle determination unit 36d, first, the axial coordinate data (θ 1 to θ 6) of the motors M1 to M6 or the three-dimensional coordinate data (X, Y, Z, θ x, θ y, and θ z) of the end effector 8 during the execution of the motion are obtained from the motion pattern stored in the axial coordinate storage unit 32a or the end effector coordinate storage unit 32 b. Next, at each time of the operation execution process, the bending angles obtained at the first joint 16 and the second joint 18 are calculated. That is, the first bend angle α 1 and the second bend angle β 1 in the first joint portion 16, and the first bend angle α 2 and the second bend angle β 2 in the second joint portion 18 are obtained.

Then, the combination of the first bending angle α 1 and the second bending angle β 1 obtained by the calculation is compared with the movable range graph 40A shown in fig. 6A, and it is determined whether or not the combination is within the movable range. Similarly, the combination of the first bending angle α 2 and the second bending angle β 2 in the second joint portion 18 is compared with the operable range graph 40B shown in fig. 6B, and it is determined whether or not the combination is within the operable range.

Note that the timing at which the joint angle determination unit 36d determines whether or not the working robot 7 is within the working range may be performed while the working device 1 is operating. In this case, whether or not the motor M is within the above-described operable range is determined based on the operation mode before the operation unit 33 outputs the operation command to each motor M. As a result of the determination, when it is determined that the combination of the first bending angle α 1 and the second bending angle β 1 in the first joint portion 16 and the combination of the first bending angle α 2 and the second bending angle β 2 in the second joint portion 18 are out of the operable range, the joint angle determination unit 36d stops the driving of the motor M, which is an actuator. This makes it possible to always monitor the presence or absence of an inoperable position that is out of the operable range in the operation mode.

Before the work robot 7 starts the work, the joint angle determination unit 36d may determine whether or not the joint angle is within the operable range, and the determination result may be displayed on the display unit 37. In this case, the joint angle determination unit 36d displays the following on the display unit 37 together with a graph showing the operation mode: that is, the combination of the first bending angle α 1 and the second bending angle β 1 at the first joint portion 16 and the combination of the first bending angle α 2 and the second bending angle β 2 at the second joint portion 18 are highlighted at the corresponding positions out of the operable range, so that the operator can easily recognize the inoperable position.

Fig. 7 shows an example of the display of the inoperable position as described above. That is, in fig. 7, a graph 41 shows an operation mode as a determination target, and here, a graph in which the horizontal axis represents the temporal change of the three-dimensional coordinate data (X, Y, Z, θ x, θ y, θ z) indicating the operation trajectory of the end effector 8 in the operation mode is shown as a time axis. In the graph 41, the range of time ta to tb indicated by hatching indicates the range of the inoperable position determined by the joint angle determination unit 36d in determining whether or not the joint angle is within the operable range.

That is, the joint angle determination unit 36d emphasizes the corresponding position of the operation mode displayed on the display unit 37 when the combination of the first bending angle α 1 and the second bending angle β 1 in the first joint unit 16 and the combination of the first bending angle α 2 and the second bending angle β 2 in the second joint unit 18 are out of the operable range. This allows the operator to easily recognize that the inoperable position exists before the operation robot 7 starts operating. In the graph 41, an example of hatching is shown as an example of emphasizing the range of the position determined to be inoperable, but various display methods can be applied as follows: a method for changing the mode and color of the background image at the corresponding position; a method of surrounding with a figure that facilitates visual recognition of the corresponding position; a method of blinking a corresponding position on a display screen, and the like.

In the above-described conventional art, the following problems are present in terms of effectively preventing mechanical interference of the movable portion. That is, in the link mechanism of the parallel link robot, universal joints for transmitting rotation around a plurality of axes are used at a plurality of positions, and the universal joints are bent to transmit the motion to the movable portion. However, in the above-described conventional technique, although the spatial position where the movable portion can operate is defined by the movable region data stored in advance, when the movable portion moves in the movable region on the data, it is not always possible to ensure the bending state obtained in the universal joint of each link mechanism. Therefore, the universal joint is forced to perform a bending operation that is not originally allowed in the mechanical structure, and interference between the mechanical parts such as the bearing part and the like constituting the joint occurs, which may cause a problem such as deformation and breakage of the mechanical parts.

The working device 1 according to the present embodiment includes: a movable portion 20 fixed to the base portion 7a via a plurality of link mechanisms 19; a plurality of actuators, i.e., motors M, that drive the plurality of link mechanisms 19; and a control unit 30 that controls these components based on the operation mode, in the working device 1, the control unit 30 is provided with a joint angle determination unit 36d, and the joint angle determination unit 36d determines whether or not the bending angle of the link mechanism at the joint portion provided in each link mechanism is within the operable range based on the device data stored in the device data storage unit 32c and the determination information stored in the determination information storage unit 32d and specifying the combination of the bending angles that are permitted in advance at the joint portion. This prevents interference between the mechanical parts such as the bearing parts, which is caused by bending operations beyond the operable range at the first joint part 16 and the second joint part 18, and prevents problems such as deformation and damage of the mechanical parts caused by forced bending operations that are not originally allowed in the mechanical structure.

As described above, the working device 1 includes: a base portion 7 a; a movable portion 20 to which the end effector 8 is attached; a plurality of link mechanisms 19 for connecting the base portion 7a and the movable portion 20; a plurality of actuators (motors M) fixed to the base portion 7a and driving the plurality of link mechanisms 19, respectively; and a control unit 30 that moves the end effector 8 by operating the plurality of actuators. Some of the plurality of link mechanisms 19 have joint portions 16 (18). The control unit 30 includes a joint angle determination unit 36d that determines whether or not the bending angles α 1(β 1, α 2, β 2) of some of the link mechanisms 19 in the joint units 16(18) are within the operable range.

The control unit 30 may include an operation pattern storage unit (32a, 32b) that stores operation patterns, and an operation unit 33 that drives the plurality of actuators based on the operation patterns stored in the operation pattern storage unit (32a, 32 b). In this case, the joint angle determination unit 36d determines whether or not the bending angles α 1(β 1, α 2, β 2) of some of the link mechanisms 19 in the joint units 16(18) are within the operable range using the operation mode.

The joint portion 16(18) may have a universal joint having a rotation shaft 21a (25a) and a rotation shaft 21b (25b) intersecting each other. The joint angle determination unit 36d may determine whether or not a combination of the bending angle α 1(α 2) around the rotation axis 21a (25a) and the bending angle β 1(β 2) around the rotation axis 21b (25b) of the joint 16(18) is within the operable range.

The work device 1 may further include a display unit 37 for displaying an operation mode. When the combination is out of the operable range, the joint angle determination unit 36d may display the position (time ta to tb) at which the combination is out of the operable range in the operation mode displayed on the display unit 37, separately from the position other than the position in the operation mode.

The joint angle determination unit 36d may stop the actuator when determining that the combination of the bending angle α 1(α 2) and the bending angle β 1(β 2) is out of the operable range.

The working device according to the embodiment has an effect of preventing interference due to bending operation beyond the operable range at the joint portion, and is useful in a field where work is performed using a working device such as a parallel link robot that includes a link mechanism that drives the movable portion via the joint portion.

Claims

1. A working device, wherein,

the work device is provided with:

a base part;

a movable portion for fitting an end effector;

a plurality of link mechanisms that connect the base portion and the movable portion;

a plurality of actuators that are fixed to the base portion, that are provided independently for each link mechanism, and that operate as power sources for the link mechanisms; and

a control unit that moves the end effector by operating the plurality of actuators,

each of the plurality of link mechanisms includes a link member, a first bendable joint portion provided at one end of the link member, and a second bendable joint portion provided at the other end of the link member,

the control unit has a joint angle determination unit that determines whether or not a bending angle of the link mechanism at each of the first joint portion and the second joint portion is within a movable range,

the joint angle determination unit determines whether or not the bending angle of the link mechanism is within a movable range based on movable range data indicating a combination of a first bending angle around the first rotation axis and a second bending angle around the second rotation axis, which correspond to a normal bending state in a universal joint corresponding to the first joint unit and the second joint unit, respectively.

2. The working device according to claim 1,

the joint angle determination unit stops the actuator when determining that the combination is out of the operable range.

3. The working device according to claim 1,

the control unit includes:

an operation pattern storage unit for storing an operation pattern; and

an operation unit that drives the plurality of actuators based on the operation pattern stored in the operation pattern storage unit,

the joint angle determination unit determines whether or not the bending angle of the link mechanism at each of the first joint portion and the second joint portion is within the movable range using the operation mode.

4. The working device according to claim 3,

the work device further includes a display unit for displaying the operation mode,

the joint angle determination unit displays a position of the operation mode out of the operable range, which is displayed by the display unit, in the operation mode, in a case where the combination is out of the operable range, in a manner distinguished from a portion other than the position in the operation mode.

5. The working device according to claim 3,